Question
Out of the two magnetic materials, 'A' has relative permeability slightly greater than unity while 'B' has less than unity. Identify the nature of the materials 'A' and 'B'. Will their susceptibilities be positive or negative?

Answer

A: Paramagnetic
B: Diamagnetic
Susceptibility:
For A: positive
For B: negative.

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Hydrogen is the simplest atom of nature. There is one proton in its nucleus and an electron moves around the nucleus in a circular orbit. According to Niels Bohr, this electron moves in a stationary orbit. When this electron is in the stationary orbit, it emits no electromagnetic radiation.The angular momentum of the electron is quantized, i.e., ⁣$\text{mvr}=\big(\frac{\text{nh}}{2\pi}\big)$ where m = mass of the electron, v = velocity of the electron in the orbit, r = radius of the orbit and n = 1, 2, 3, .... When transition takes place from $K^{th}$ orbit to $J^{th}$ orbit, energy photon is emitted. If the wavelength of the emitted photon is $\lambda$ we find that $\frac{1}{\lambda}=\text{R}\bigg[\frac{1}{\text{J}^2}-\frac{1}{\text{K}^2}\bigg]$where find that On a different planet, the hydrogen atom's structure was somewhat different from ours. The angular momentum of electron was $\text{P}=2\text{n}\Big(\frac{\text{h}}{2\pi}\Big)$ i.e., an even multiple of $\Big(\frac{\text{h}}{2\pi}\Big)$.
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In the year 1939, German scientist Otto Hahn and Strassmann discovered that when an uranium isotope was bombarded with a neutron, it breaks into two intermediate mass fragments. It was observed that, the sum of the masses of new fragments formed were less than the mass of the original nuclei. This difference in the mass appeared as the energy released in the process. Thus, the phenomenon of splitting of a heavy nucleus (usually A > 230) into two or more lighter nuclei by the bombardment of proton, neutron $\alpha$-particle, etc. with liberation of energy is called nuclear fission.
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$\big[\because \ _{92}\text{U}^{236}= \text{Unstable nucleus}\big]$
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